Inductor for train control systems



Dec. 1, 1931. x. RICE INDUCTOR FOR TRAIN CONTROL SYSTEMS Filed April 26, 1926 Jwmmio c FML/P X ff/OE Patented Dec. 1, 1931 UNITED STATES PATENT OFFICE H PHILIP, x. RICE, or DANVILLE, ILLINOIS, ASSIGNOR To THE MILLER TRAIN CONTROL 3 CORPORATION, or STAUNTON, VIRGINIA, A CORPORATION or VIRGINIA INDUCTOR FOR TRAIN CONTROL SYSTEMS Application filed. April 26, 1926. Serial No. 104,801.

This invention relates to train control systems and more particularly to inductors or track elements for induction train control systems.

An object of the present invention is to provide an inductor for use on inductive train control systems that is capable of operating in conjunction with locomotive apparatus or systems of dilterent types.

Among the most frequently used inductive train control systems now known are the alternating' current system described and claimed in my copending application filed May 3rd, 1926, Serial N0. 106,478, and the auto manual direct current unidirectional flux, motional-dynamic system of the General Railway Signal Company. The imidirectional flux type'mentioned comprises a magnetized receiver-generator carried on the vehicle, and a track armature or inductor of iron over which the receiver moves. The receiver-generator has a generating winding adapted to generate an electric voltage cycle when passing over saidtrack armature, this result being due to themotional-dynamic phenomena which occurs whenever a magnet has the reluctance of its magnetic path suddenly altered.

Each ofthese systems employs an inert track element, that is a trackelement formed ofmagnetizable metal which will cause a change in the receiver carried by the locomotive, and which is provided with means, such as a coil or coils, to permit the reoeiverto pass over the track element withoutbeing affected when aclear condition exists in the lock.

In railway practice trains equipped with onetype of train control mechanism frequently travel over tracks of another railroad which may be equipped with another system of train control, and by means of the inductor forming the subj cot-matter of the present invention either type of locomotive apparatus may be actuated to stop the train if paratus of the motional unidirectional flux type referred to above, and

Figure 3 is a similar view showing the locomotive carried apparatus of Figure 1 in position over an ordinary inductor.

Referring to the drawings the reference numeral 1 designates generally a locomotive which is mounted on wheels 2 and adapted to travel on a track 3 in the usual manner. The

train control system described and claimed in my copendmg application employs alternating current on the vehicle which may be obtained from a generator 4 or other source to energize a primary coil of a receiver 5. This receiver is an open core transformer adapted to have its secondary voltage and current controlled by flux-directional effect of railroad-side inductors in a manner to be described. The secondary current of the receiver normally retains an electro pneumatic valve in box 6 in a closed position and this valve in turn controls a pneumatically operated brake valve actuator 7.

In the motional unidirectional flux type of vehicle carried apparatus there is provided an iron core 8 forming the receiver and having a primary coil 9. This primary coil is energized from a source of current 10 which is connected thereto by lead Wires 11 and causes the iron core 8 to become a magnet of unidirectional polarity. Adjacent the other end of the corethere is provided a coil 12 which is conected to a relay 13 adapted to actuate the train control mechanism (not shown). The relay is normally held in closed or proceed position from a source of energy 12' and as long as this current remains unneutralized the relay remains closed. The unidirectional flux flowing to the secondary coil 12 from the primary coil 9 has no efi'ect on the latter.

Referring to Figure 3 of the drawings Wherein-the alternating flux type of receiver 1s more clearly illustrated the receiver con-. slsts of a pair of rods or plates 14 which are normally spaced from each other. Coils l5 and 16 are connected to two diagonally opposite ends of the two plates and these coils are connected to the source of current 4 by. lead wires 17. The other ends of the coils.

are connected to each other by a Wire18 and a back yoke is arranged 1 betweenjthe two rods. The said diagonally opposite ends ofthe two rods thus'form poles 20 and 21 of the primary coil. The other two ends of the rods or platesare likewise provided with coils 22 and 23 which are connected to the train control apparatus, described as a valve mag netfi24 b I leadwires25 These two coils are connected at their opposite ends by a suitable V apair, of spaced laminated plates 29 arranged beside the track and adapted to be disposed beneath the corresponding platesof the receiver when the locomotive passes over it. These plates or cores areprovided withsui ablecoils 30 connected by lead wires 31 to a condenser 32:-

relay switch arm 33 is ar rangedjin the connecting wires 31 and is adapted tobc held in closed position b yialine relay (not shown')-- when the block is Iclear.

Briefly, whenpassing over an opencircuited track element the proximity of the plates 29 I to thereceiv'er causes the fluxto flow from the inchictorelemen -V t frorn the tpole:

pole'20b'f the primary-coil to theupper inductor plate 29 as indicated by thearrows '34 thence "throughthis' member to the secondary pole 27 of the receiverl thence through the receiver to thepolei28', thence'to thelower 1229- asi-fndicatedby the arrow 35,-thence through this' neniber to the pole of-the receiver and [the'nce to: its source It wilflbeseenthatthechrection ottlow through the; secondary is thus reversed,= the flux flowing from the pole 27 to the PiOle 28 instead 7 '28;5='QO the pole 27 This re yersalofthe. flower flux, or tendency to re verse, either reduces the secondary current to a point; where it pas es through azero value or' reduces it toward zero'to'such an amount that it becomesinsufiicient to holdthe control valve 6 in closed positon. I lVhen-j the track is clearthecondenser 32 reflects thereceived current to the coils 30 and the, normal conditions in the. receiver are :not affected;

The operation of the type of receiver shown in dotted lines in Figure 2 of the drawings depends upon the movement of the receiver relative to the track element to generate or induce a single cyclev of current in the sec ondary of the receiverif the'inductor is in stop condition. In this type of apparatus the current is generated by motion insubstantially the same manner as by a dynainjo armature in motionxWhen the receiver 8 passes "over a track element the quantity of flux passing through the flux path is increased.

For this purpose "the track element is provided with a pair of poles 36 and is formed 'ofinate'rial of high permeability. Between the-poles the inductor is provided witha coil 37 and this coil is connected to a relay switch 38 by a suitableleadwire 39., the switch being controlled by the line relay (not shown) in the usual manner The switch is adapted to engage a contact 40 carried by a lead wire Q1 and connected to the opposite end of the coil. A reactor coil 4:2. may; be arranged in either of these wires condenser 43 may bridged across the reactor, coil lbylsuitable lead wires g The inductor shown in Figure 2is also shown modified to perform the functions of the inductor shown inFigure'3 and: to function with a :receiver of thealternating flux type As'shown the ends of thetra-ck side element beyond thepoles 36 are reduced in cross section as at 45 and provided with suit able coils d6. A second laminated plate a7 is arranged parallel to the member 36 and is providedwith coils 4-8 adjacent each end. The coils of each plate are connected to the coils of the other-plate by suitable wireslt) and the ends of the coils. are connected to lead wires 50 and 51 which are in turn connected' to condensers 52. Beyond the condensers one wire of each pairisprovided with a contact 53- and the other wire is connected to a relay switch 54 adapted to be controlled by the line relay (not shown), a v V r The operation 40f the vdevicew vill be 7 apparent from the foregoing description. As stated, themagnetio flux generated by the coil 9 of a unidirectionalv polaritysimilar to a permanent magnet and the unidirectional flux flowing through the coil 12 is not employed toretain the relay 13 closed but current from the separate sourcel12? is employed 'for this purposes When thisreceiver passes over a track element the high permeability of that portion of the core formed byv th e poles-36 and the connecting" section causes a change of flux quantityin the receiver and induces a-voltage in coil 12. ;.Acs'theireceiver passes beyond the inductor the receiver flux decreases thus inducing-asecondary voltage reverse to the first mentioned induced voltage.

" One or the other of-these induced voltagesis employed to neutralize the steady unidirec;

tional relay current thus allowing the relay to open to actuate the train control mechanism. To give a clear signal the coil 37 is employed to choke out flux variations in the inductor. With the switch 38 controlled by the line relay in closed position the choke current in the coil 37 and its circuit opposes the normal flux of the receiver and prevents this flux from being changed a suflicient amount to actuate the relay. The reactor coil 42 has no serious effect on the choke current of a (clear) inductor in a system of the unidirectional flux type because of the low frequency employed. This coil is employed 'for the purpose of preventing the switch 38 from completely short circuiting the clear circuit when high frequency currents are induced by the alternating flux type of receiver shown in Figure 3 of the drawings.

The operation of the alternating flux type of receiver has been described in connection with Figure 3 of the drawings and when employed in connection with the inductor shown in Figure 2, the operation is essentially the same. If the receiver shown in Figure 3 of the drawings passes over the inductor with the contacts 54- in open position the flux from the pole 20 passes through the plate or core 47 and returns to the receiver through the secondary pole 27 thus reversing the normal direction of flow in the secondary of the receiver. When the track is clear and the contacts 54 are closed by the line relay the condensers 52 reflect the current through the coils 46 and 48 preventing any change in the normal flow of current through the receiver As stated the reactor coil 42 prevents the coil 37 and its condenser 43 from being short circuited when excited by high frequency energy from a receiver of the alternating flux type but does not prevent it from becoming short circuited when excited by the low frequency cycle employed in the unidirectional system.

It is to be understood that the form of my invention herewith shown and described is to be taken as a preferred example of the same and that various changes in the shape,

size, and arrangement of parts may beresorted to without departing from the spirit of the invention or the scope of the subjoined claims. v

I claim:

1. A track element for train control systems comprising an inductor adapted to cause generation of current in a coil of a vehicle carried receiver of the unidirectional flux type by virtue of motion of said receiver ith respect to said inductor, said inductor having cores parallel to the cores of a receiver of the alternating flux type and being adapted to redirect the flow of flux through said alternating flux receiver.

' 2. A track element of the character described in claim 1 wherein coils are arranged on said inductor and adapted to render said inductor inoperative.

3. A track element for train control systems comprising an inductor formed of a pair of cores, one of said cores being provided with a portion of high permeability and adapted to generate current in a vehicle carried receiver of the unidirectional flux type by virtue of movement of said receiver with respect to said inductor, the remaining portion of said core and the other core being adapted to redirect the flow of flux through the cores of a receiver of the alternating flux type.

4. A track element for train control systems comprising an inductor formed of a core of high permeability and adapted to generate current in a vehicle carried receiver of the unidirectional fiux type by virtue of movement of said receiver with respect to aid inductor, said core being provided with ends of reduced cross-section, a second core of smaller cross sectional area than said first mentioned core, the end portions of said first mentioned core and said second core being adapted to redirect the flow of flux through the cores of a receiver of the alternating flu type coils arranged on the ends of each core, and condensers connected to said coils whereby a receiver of the alternating flux type may be rendered inoperative in respect to initiation of brake application or speed reduction when said coils are connected to said condensers.

5. A device constructed in accordance with claim 3 wherein the portion of said first mentioned core of high permeability is provided with a coil arranged in a closed circuit and a reactor coil is arranged in said circuit.

6. A device constructed in accordance with claim 3 wherein the first mentioned portion of said inductor is relatively short and elevated and the second mentioned portion thereof is relatively long and depressed.

'7. In a train control system of the intermittent inductive type, a track element adapted to influence car-carried receivers either of the unidirectional. flux type or of the alternating flux type, and comprising, a magnetic core acting to generate a voltage in the coil of the receiver of the uni-directional flux type by virtue of the movement of the receiver over said magnetic core, said core also acting to change the fin); in'the core of the receiver of the alternating flux type, and means for rendering the core of said track element ineffective to influence said receivers of either type and comprising control circuits automatically closed under safe traiiic conditions and opened under danger traiiic conditions, one of said circuits including a condenser.

In testimony whereof I afiiz; my signature.

PHILIP X. RICE. 

